Aqueous fluoropolymer dispersions are used for impregnation, coating, and the like. For the purpose of improving mechanical stability or storage stability, or controlling viscosity, such aqueous dispersions contain nonionic surfactants.
Various nonionic surfactants have been conventionally known.
For example, Patent Literature 1 discloses a surfactant that has a secondary alkyl group or a primary alkyl group having aside chain as a hydrophobic group, and includes a T-structure in which a hydrophilic group chain is bonded to the hydrophobic group. Further, Patent Literature 2 discloses an isotridecyl ether surfactant which is used as a foam-suppressing surfactant. The isotridecyl ether surfactant includes an at least triply branched isotridecyl and has an oxypropylene group.
Patent Literature 3 suggests a fluororesin aqueous dispersion composition containing an aliphatic polyoxy alkylene ether dispersant which has a 50% decomposition temperature of not less than 250° C.
Patent Literature 4 suggests an aqueous fluoropolymer dispersion containing a fluoropolymer, an aqueous medium, and a certain polyoxy alkylene alkyl ether stabilizer.